d1310b2e0c
There is now extent_map for mapping offsets in the file to disk and extent_io for state tracking, IO submission and extent_bufers. The new extent_map code shifts from [start,end] pairs to [start,len], and pushes the locking out into the caller. This allows a few performance optimizations and is easier to use. A number of extent_map usage bugs were fixed, mostly with failing to remove extent_map entries when changing the file. Signed-off-by: Chris Mason <chris.mason@oracle.com>
56 lines
1.3 KiB
C
56 lines
1.3 KiB
C
#ifndef __EXTENTMAP__
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#define __EXTENTMAP__
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#include <linux/rbtree.h>
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#define EXTENT_MAP_LAST_BYTE (u64)-4
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#define EXTENT_MAP_HOLE (u64)-3
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#define EXTENT_MAP_INLINE (u64)-2
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#define EXTENT_MAP_DELALLOC (u64)-1
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struct extent_map {
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struct rb_node rb_node;
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/* all of these are in bytes */
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u64 start;
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u64 len;
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u64 block_start;
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unsigned long flags;
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struct block_device *bdev;
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atomic_t refs;
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int in_tree;
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};
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struct extent_map_tree {
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struct rb_root map;
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struct extent_map *last;
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spinlock_t lock;
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};
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static inline u64 extent_map_end(struct extent_map *em)
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{
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if (em->start + em->len < em->start)
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return (u64)-1;
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return em->start + em->len;
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}
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static inline u64 extent_map_block_end(struct extent_map *em)
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{
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if (em->block_start + em->len < em->block_start)
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return (u64)-1;
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return em->block_start + em->len;
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}
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void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask);
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struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
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u64 start, u64 len);
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int add_extent_mapping(struct extent_map_tree *tree,
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struct extent_map *em);
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int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
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struct extent_map *alloc_extent_map(gfp_t mask);
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void free_extent_map(struct extent_map *em);
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int __init extent_map_init(void);
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void extent_map_exit(void);
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#endif
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